Roller adjusting mechanism



July 1, 1969 CERASAN] 3,452,912

' ROLLER ADJUSTING MECHANISM Filed March 2, 1967 AMER/C0 J. CERASA/V/ INVENTOR.

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ATTORNE United States Patent 3,452,912 ROLLER ADJUSTING MECHANISM Americo J. Cerasani, Rochester, N.Y., assignor to Itek Corporation, Lexington, Mass., a corporation of Delaware Filed Mar. 2, 1967, Ser. No. 620,187 Int. Cl. B65h 17/20 US. Cl. 226-176 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to a device for adjusting the normal force between an upper driven roller and a lower idler roller, which lower roller may have a lower shaft positioned at or beneath the surface of a web processing liquid which is applied to the web material such as photosensitive paper being driven through the nip of the rollers.

Background of the invention In the prior art, a pair of rollers situated within a proc essing tank are positioned whereby the lower roller carries processing liquid up to the nip of the rollers and applies the liquid to web material passing through the nip. Since the lower roller spindle is often submerged in the processing liquid, it is desirable to drive the upper roller rather than the lower roller to avoid the use of a sealed journal or fluid proof bearing for supporting the lower roller drive spindle in the wall of the tank containing the processing fluid. These bearings may present maintenance problems and'accordingly their use is undesirable. Where the upper roller shaft position is fixed because of its direct connection to a drive mechanism, it is necessary to spring bias the lower roller against the upper one. However, especially where the roller pair is positioned near the bottom of a processing tank, it is diflicult to gain access to the lower roller for easily and accurately adjusting the mechanical biasing pressure of the lower roller against the upper roller.

Summary of the invention In the disclosed embodiment of the invention, the upper driven roller is rigidly mounted with respect to a roller frame and the lower roller is mechanically biased against the upper roller through the use of an elongated rigid mechanical link which grips the lower roller shaft and which is placed in tension by means of a spring coupled between the roller frame and the under side of the upper remote portion of the mechanical link. A screw member adjustably alters the link tension and hence the roller bias by changing the degree of compression of the spring.

Other objects and advantages of the invention will become apparent as the following description taken in conjunction with the following figures proceeds:

FIGURE 1 discloses a front view of the illustrated embodiment. FIGURE 2 discloses a side view of the illustrated embodiment.

In order to simplify the figures, both the processing tank and the roller frame are shown broken. FIGURE 1 discloses upper roller 1 coupled to roller drive motor 2 situated outside of processing tank 3 by means of spindle 4, which spindle passes through a cylindrical bore 6 in roller frame 7. Lower roller 8 has its spindle 9 loosely positioned within an elongated slot 11 formed in roller frame 7 which frame is positioned within tank 3 so that roller 8 carries the liquid within the processing tank up to roller nip 12 so that it is applied to the web material passing through.

An elongated mechanical link 13 has an extended aperture 14 as best shown in FIGURE 2. The lowermost secice tion of aperture 14 embraces spindle 9 at point 16 but does not contact spindle 6 of upper roller 1 due to elongated aperture 14. A well 17 is formed within roller frame 7 and spring '18 is situated therein as illustrated. Screw member 19 having a stud projection 20 projects into well 17 as shown and is connected to the upper portion of mechanical link '13 through a tapped hole formed therein It may now be seen that the degree of compression of spring 18 may be easily and accurately adjusted by turning nut 21. Since the compressive force of the spring will be transferred to spindle 9 of lower roller 8 via link 13, it follows that the roller bias may be conveniently and accurately adjusted at the remote upper portions of the frame without removing the frame from the tank. Spring 18 is maintained in its correct position through the use of elongated stud'20 and possible spring buckling is avoided. Preferably, the structure shown in the figures is duplicated at the other ends of the rollers to maintain pressure uniformity along the length of the nip. For certain applications, such as processing web material of changing thickness across its width, non-uniformity of pressure or gap width may be selectively provided by differential adjustment of the nuts.

I claim:

1. In a processor for transporting and processing photosensitive sheet material:

(a) a photosensitive film developing tank;

(b) a roller frame positioned within said developing tank;

(c) a first roller rotatably fitted within said roller frame;

(d) means coupled to said first roller for driving said first roller;

(e) a second roller positioned adjacent said first roller to form a nip with said first roller at one side of said first roller; and

(f) pressure means coupled to said second roller and positioned on the other side of said first roller for varying the normal force between said rollers at the nip thereof, said pressure means further comprising a rigid elongated link member coupled to said second roller together with a tensioning means coupled to said rigid link for altering the tension in said rigid link thereby to conveniently alter said normal force between said rollers at a position separated from said second roller.

2. The combination as set forth in claim 1 wherein said tensioning means further comprises a support member for said rigid link and a spring coupled between said support member and said rigid link for inducing tension in said link.

3. The combination as set forth in claim 2 further including a movable member coupled between said spring and said rigid link for altering the spring force transmitted to said rigid link.

4. The combination as set forth in claim 3 wherein said movable member comprises a screw coupled between said rigid link and said spring.

5. The combination as set forth in claim 4 wherein said spring is a cylindrical coil spring and said screw has a stud portion having a diameter smaller than the screw diameter, which stud is fitted within said cylindrical coil spring to properly maintain the position of said spring with respect to said screw.

6. In a processor for transporting sheet material:

(a) a roller frame;

(b) a first roller rotatably fitted within said roller frame;

(c) means coupled to said first roller for driving said first roller;

((1) a second roller positioned adjacent said first roller to form a nip with said first roller at one side of said first roller; and

(e) pressure means coupled to said second roller and positioned on the other side of said first roller for varying the normal force between said rollers at the nip thereof, said pressure means further comprising a rigid elongated link member coupled to said second roller together with tensioning means coupled to said rigid link for altering the tension in said rigid link thereby to conveniently alter said normal force between said rollers at a position separated from said second roller.

7. The combination as set forth in claim 6 wherein said tensioning means further comprises a support member for said rigid link and a spring coupled between said support member and said rigid link for inducing tension in said link.

8. The combination as set forth in claim 7 further including a movable member coupled between said spring and said rigid link for altering the spring force transmitted to said rigid link.

9. The combination as set forth in claim 8 wherein said movable member comprises a screw coupled between said rigid link and said spring.

10. The combination as set forth in claim 9 wherein said spring is a cylindrical coil spring and said screw has a stud portion having a diameter smaller than the screw diameter, which stud is fitted within said cylindrical coil spring to properly maintain the position of said spring with respect to said screw.

References Cited UNITED STATES PATENTS 11/1949 Pratt 226-187 X 9/1964 Nordman 226-176 US. Cl. X.R. 

